As the techniques for pediatric cardiac surgery improve and the results also, more complex operations can be performed. Increasingly the limiting factors for survival are not technical surgical issues. Two of the most important factors today are blood loss and the length of time required for the operation. At present, techniques for performing vascular anastomoses are with sutures. These bleed at the end due to the disturbance in the clotting system caused by the heart-lung machine. Reducing this bleeding will reduce the risk of cardiac surgery in this group of patients. A technique to reduce this blood loss may be provided by new laser technology. Using a unique feedback system the power output of the laser can be controlled. This allows the use of a bioadhesive which seals the suture holes of a conventional anastomosis and the incision itself. In the Phase I study, the feasibility of this approach has been demonstrated. Anastomoses can be made significantly more blood tight using this technology with fluid loss being reduced by 65 to 75%. Phase II will build on these results and address the question of whether the laser-treated anastomoses can grow at the same rate as the surrounding tissue to ensure that there is no constriction at the sites of previous surgery. The ability to grow is obviously a crucial property of neonatal tissue. This study will also determine some in vivo end- points such as how much time is saved during the operation and how much blood is required by the individual following surgery. This will give a good indication of the reduction in demands on the blood transfusion service and which can be expected from the implementation of the new technology. PROPOSED COMMERCIAL APPLICATION: The development of neonatal vascular anastomotic procedures using laser welding and sealing technology will be applicable to all cardiovascular surgical procedures including CABG and repair of aortic dissection. Other applications include sealing of leakage in bowl and esophageal anastomoses.